Sr2SiO4:Sm3+红色荧光粉的发光特性

用高温固相法合成了Sr2SiO4:Sm3 红色荧光粉,并研究粉体的发光性质.发射光谱由位于红橙区的3个主要荧光发射峰组成,峰值分别位于570,606nm和653nm,对应了Sm3 的4G5/2→6H5/2,4G5/2→6H7/2和4G5/2→6H9/2特征跃迁发射,606nm的发射最强.激发光谱表现从350 nm到420nm的宽带,可以被近紫外光辐射二极管(near-ultraviolet light-emitting diodes,UVLED)管芯产生的350～410 nm辐射有效激发.研究了Sm3 掺杂和不同电荷补偿剂对样品发光亮度的影响,Sm3 掺杂摩尔分数为6%、电荷补偿剂为Cl-时的效果最好.Sr2SiO4:Sm3 是一种适用于白光LED的红色荧光粉.     

氟氧硅酸盐玻璃钐离子的光谱参数计算和荧光光谱分析

本工作针对Sm3+掺杂氟氧硅酸盐(NBZASB)玻璃进行了制备合成,对玻璃的吸收和荧光光谱展开了测试与分析.根据吸收光谱进行了光谱参数的计算,获得了氟氧硅酸盐玻璃中Sm3+离子的晶场调节参数,进而计算得到各能级光谱参数,其中钐离子4G5/2能级到6H9/2和6H7/2到两个能级跃迁的自辐射跃迁几率分别为187 s-1和107s-1,荧光分支比分别达到47％和27％.在商用365 nm和254 nm紫外光激发下Sm3+掺杂NBZASB玻璃呈现明亮的橙红色光,发射光谱表明其最强发射峰位于600 nm.激发光谱表明,氟氧硅酸盐玻璃中Sm3+离子的有效受激波长范围覆盖了从345 nm紫外光到472 nm绿色光等六个激发峰的宽光谱区域,多种商用激光器、激光二极管及发光二级管都可以有效激发Sm3+掺杂NBZASB玻璃.     

红色荧光粉Ba2–xB2O5:xSm3+的制备及发光性能

采用高温固相法合成了Ba2–xB2O5:xSm3+红色荧光粉。研究了Sm3+掺杂量对样品发光性质的影响。结果表明,合成物质为纯相Ba2B2O5晶体结构。主激发峰为342nm(6H5/2→4H9/2)、359nm(6H5/2→4D3/2)、372nm(6H5/2→6P7/2)、400nm(6H5/2→4F7/2)、436nm(6H5/2→4G9/2)、450～510nm(6H5/2→4I13/2,4I9/2,4I11/2,4G7/2)。主发射为550～575nm(4G5/2→6H5/2)、580～620nm(4G5/2→6H7/2)及630～660nm(4G5/2→6H9/2),其中以400nm激发的峰值最大。随着Sm3+掺量x的增大,发光强度先增大后减小,在x=0.06时达到最大值。分析表明其浓度猝灭的机理是电偶极–电四极相互作用。     

Preparation and Luminescence Properties of Ba_（2-x）B_2O_5：xSm~（3＋） Red-Emitting Phosphor

采用高温固相法合成了Ba2–xB2O5：xSm3＋红色荧光粉。研究了Sm3＋掺杂量对样品发光性质的影响。结果表明,合成物质为纯相Ba2B2O5晶体结构。主激发峰为342nm（6H5/2→4H9/2）、359nm（6H5/2→4D3/2）、372nm（6H5/2→6P7/2）、400nm（6H5/2→4F7/2）、436nm（6H5/2→4G9/2）、450～510nm（6H5/2→4I13/2,4I9/2,4I11/2,4G7/2）。主发射为550～575nm（4G5/2→6H5/2）、580～620nm（4G5/2→6H7/2）及630～660nm（4G5/2→6H9/2）,其中以400nm激发的峰值最大。随着Sm3＋掺量x的增大,发光强度先增大后减小,在x=0.06时达到最大值。分析表明其浓度猝灭的机理是电偶极–电四极相互作用。     

Sr_3Y(PO_4)_3∶Sm~(3+)荧光粉的制备及发光特性

采用高温固相法合成Sr3Y1--x(PO4)3∶xSm3+发光材料。X射线衍射表明,1 400℃高温烧制的Sr3Y(PO4)3荧光粉为纯相晶体结构。荧光粉的主激发峰为343、360、373、400、436和468nm;主发射峰为550~575nm(4 G5/2→6 H5/2)、580~620nm(4 G5/2→6 H7/2)和630~660nm(4 G5/2→6 H9/2)。荧光粉在599nm附近有很强的发射,呈现良好的红橙光,符合广泛应用的UV-LED芯片。研究了不同Sm3+掺杂量对样品发射谱的影响,发光强度随着Sm3+掺杂量的增大而增强。当掺杂量x=0.04时,发光强度最强。继续增大Sm3+掺杂量,样品的发光强度反而减弱,即出现浓度猝灭现象。根据Dexter理论,猝灭机理为离子之间的能量转移作用。     

燃烧法制备白光LED用红色荧光粉SrBPO_5∶Sm~(3+)及发光性能

用H3BO3作为助熔剂、尿素为燃料,采用燃烧法在较低的起始温度(650℃)下制备了的纳米级SrBPO5∶Sm3+红色荧光粉。研究了该荧光粉样品的相结构、形貌和发光特性。结果表明:SrBPO5∶Sm3+样品属于三方晶系,空间群为P3121;该荧光粉平均粒径为200nm、分散性较好。样品在近紫外光404nm的激发下发射红光,发射主峰位于558、596和645nm处,分别对应于Sm3+的4 G5/2→6 H5/2、4 G5/2→6 H7/2和4 G5/2→6 H9/2的跃迁;当Sm3+的最佳摩尔掺杂量为10%,对于既可作为助熔剂又是原料的H3BO3过量0.8%时,样品的发射峰强度最强。SrBPO5∶Sm3+有望成为近紫外激发的白光LED用新型红色荧光粉。     

钐离子掺杂CaO-MgO-SiO2系微晶玻璃的制备及其发光特性

制备了一种新型的以透辉石为主晶相的钐离子激活发光微晶玻璃,采用X射线衍射仪、扫描电子显微镜和荧光光谱仪研究了热处理温度对微晶玻璃的结构及发光性能的影响.结果表明:钐离子激活发光微晶玻璃在近紫外、蓝光的激发下可以发出红色光,其564,601,648nm和710nm发射峰分别对应于Sm3 的4G5/2→6HJ(J=5/2,7/2,9/2,11/2)跃迁,随着热处理温度的升高和透辉石晶体逐渐析出,光谱的谱线位置没有变化,强度明显增强.同时发现该基质中,当Sm2O3掺杂量超过0.100%(摩尔分数)时出现浓度猝灭现象.     

白光LED用K_2ZnSiO_4:Sm~(3+)橙红色荧光粉的制备及发光性能

用溶胶-凝胶法合成白光LED用K2Zn Si O4:Sm3+橙红色荧光粉,研究了样品结构及发光性能。X射线衍射分析表明,微量Sm3+掺杂的样品主晶相为正交晶系结构的K2Zn Si O4。该荧光粉能被近紫外光有效激发,在403 nm激发下,发射光谱由4个发射峰组成,最强峰位于605 nm处,是由Sm3+的4G5/2→6H7/2跃迁引起的。增大Sm3+掺杂量,发光强度先增大后减小,Sm3+最佳掺杂摩尔分数为7%。随着Sm3+掺杂量的增加,样品的色坐标基本不变,位于橙红光区。     

白光LED用球形钼酸钙粉体的控制合成及特性(英文)

以去离子水和无水乙醇的混合溶液为溶剂,采用水热法成功合成出白光LED用球形CaMoO4基质粉体,制备了Eu3+、Sm3+、Pr3+掺杂的CaMoO4红色荧光材料。对CaMoO4∶Re3+(Re=Eu,Sm,Pr)荧光粉的物相、微观形貌和发光性能进行表征。结果表明:180℃水热反应24h,水与乙醇体积比为3∶1,pH=7.0时可控制合成出规则球形CaMoO4粉体。CaMoO4∶Eu3+粉体在395nm紫外光和465nm蓝光激发下,最强的红光发射峰位于618nm处,对应于Eu3+的5 D0→7 F2跃迁。CaMoO4∶Sm3+荧光粉激发峰为406和480nm,最强的红光发射峰位于649nm处,对应于Sm3+的4 G5/2→6 H9/2跃迁。CaMoO4∶Pr3+在453nm蓝光激发下,其最强红光发射峰位于655nm处,对应于Pr3+的3 P0→3 F2跃迁。而掺杂作为电荷补偿剂的碱金属Li+,可以有效提高CaMoO4∶Re3+(Re=Eu,Sm,Pr)荧光粉的发射强度。由此可知,CaMoO4∶Re3+(Re=Eu,Sm,Pr)有望成为白光LED用红色荧光粉。     

钐硼硅酸盐玻璃组成对吸收谱线的影响

利用传统方法制得了高Sm2O3含量的硼硅酸盐玻璃,讨论了稀土含量以及玻璃组成对稀土玻璃吸收光谱曲线的影响。结果表明:钐硼硅酸盐玻璃的特征吸收峰强度随着Sm2O3含量的增加而增强,同时吸收峰展宽;随着硅硼比的增加,也使得吸收峰的宽化程度增加。为制备对特定波长激光具有高吸收强度的特种光学玻璃提供了依据。     

Many Drugs of Abuse May Be Acutely Transformed to Dopamine,Norepinephrine and Epinephrine In Vivo

It is well established that a wide range of drugs of abuse acutely boost the signaling of the sympathetic nervous system and the hypothalamic–pituitary–adrenal (HPA) axis, where norepinephrine and epinephrine are major output molecules. This stimulatory effect is accompanied by such symptoms as elevated heart rate and blood pressure, more rapid breathing, increased body temperature and sweating, and pupillary dilation, as well as the intoxicating or euphoric subjective properties of the drug. While many drugs of abuse are thought to achieve their intoxicating effects by modulating the monoaminergic neurotransmitter systems (i.e., serotonin, norepinephrine, dopamine) by binding to these receptors or otherwise affecting their synaptic signaling, this paper puts forth the hypothesis that many of these drugs are actually acutely converted to catecholamines (dopamine, norepinephrine, epinephrine) in vivo, in addition to transformation to their known metabolites. In this manner, a range of stimulants, opioids, and psychedelics (as well as alcohol) may partially achieve their intoxicating properties, as well as side effects, due to this putative transformation to catecholamines. If this hypothesis is correct, it would alter our understanding of the basic biosynthetic pathways for generating these important signaling molecules, while also modifying our view of the neural substrates underlying substance abuse and dependence, including psychological stress-induced relapse. Importantly, there is a direct way to test the overarching hypothesis: administer (either centrally or peripherally) stable isotope versions of these drugs to model organisms such as rodents (or even to humans) and then use liquid chromatography-mass spectrometry to determine if the labeled drug is converted to labeled catecholamines in brain, blood plasma, or urine samples.     

Sapindaceae,cyanolipids, and bugs

Scentless plant bugs (Heteroptera: Rhopalidae) are so named because adults of the Serinethinae have vestigial metathoracic scent glands. Serinethines are seed predators of Sapindales, especially Sapindaceae that produce toxic cyanolipids. In two serinethine species whose ranges extend into the southern United States,Jadera haematoloma andJ. sanguinolenta, sequestration of host cyanolipids as glucosides renders these gregarious, aposematic insects unpalatable to a variety of predators. The blood glucoside profile and cyanogenesis ofJadera varies depending on the cyanolipid chemistry of hosts, and adults and larvae fed golden rain tree seeds (Koelreuteria paniculata) excrete the volatile lactone, 4-methyl-2(5H)-furanone, to which they are attracted.Jadera fed balloon vine seeds (Cardiospermum spp.) do not excrete the attractive lactone. Loss of the usual heteropteran defensive glands in serinethines may have coevolved with host specificity on toxic plants, and the orientation ofJadera to a volatile excretory product could be an adaptive response to save time.Mention of a commercial product does not consititute an endorsement by the USDA.     

2008～2009年世界塑料工业进展

收集了2008年7月～2009年6月世界塑料工业的相关资料,介绍了2008～2009年国外塑料工业的发展情况,提供了世界塑料产量、消费量及全球各类树脂的需求量及产能情况。按通用热塑性树脂(聚乙烯、聚丙烯、聚苯乙烯、聚氯乙烯、ABS树脂)、工程塑料(尼龙、聚碳酸酯、聚甲醛、热塑性聚酯、聚苯醚)、特种工程塑料(聚苯硫醚、液晶聚合物、聚醚醚酮)、通用热固性树脂(酚醛、聚氨酯、环氧树脂、不饱和聚酯树脂)不同品种的顺序,对树脂的产量、消费量、供需状况及合成工艺、产品应用开发、树脂品种的延伸及应用的进一步扩展等技术作了详细介绍。     

ICP-MS法测定地球化学样品中As、Cr、Ge、V等18种微量痕量元素的研究

建立了测定地球化学样品中包括As、Cr、Ge、V等18种微量、痕量元素的ICP-MS方法。地化试样用HF-HNO3混酸分解后,以1 1 HNO3溶解干渣。由于制样不使用盐酸,避免了Cl对As、Cr、Ge、V的质谱干扰。用国家一级地球化学标准物质GBW 07309制备溶液优化仪器工作参数,并用于校准。方法测定限(6s)为:0.007~6.4μg/g,精密度(RSD%,n=12)为:29%~9.4%,经过国家一级地球化学标准物质的分析验证,结果与标准值吻合。方法已应用于国土资源调查的试样分析。     

Direct observation of freeze-thaw instability of latex coatings via high pressure freezing and cryogenic SEM

Despite its industrial importance, the subject of freeze-thaw (F/T) stability of latex coatings has not been studied extensively. There is also a lack of fundamental understanding about the process and the mechanisms through which a coating becomes destabilized. High pressure (2100 bar) freezing fixes the state of water-suspended particles of polymer binder and inorganic pigments without the growth of ice crystals during freezing that produce artifacts in direct imaging scanning electron microscopy (SEM) of fracture surfaces of frozen coatings. We show that by incorporating copolymerizable functional monomers, it is possible to achieve F/T stability in polymer latexes and in low-VOC paints, as judged by the microstructures revealed by the cryogenic SEM technique. Particle coalescence as well as pigment segregation in F/T unstable systems are visualized. In order to achieve F/T stability in paints, latex particles must not flocculate and should provide protection to inorganic pigment and extender particles. Because of the unique capabilities of the cryogenic SEM, we are able to separate the effects of freezing and thawing, and study the influence of the rate of freezing and thawing on F/T stability. Destabilization can be caused by either freezing or thawing. A slow freezing process is more detrimental to F/T stability than a fast freezing process; the latter actually preserves suspension stability during freezing. Presented at the 82nd Annual Meeting of the Federation of Societies for Coatings Technology, October 27–29, 2004 in Chicago, IL. Tied for first place in The John A. Gordon Best Paper Competition.     

Insect antifeedant properties of anthranoids from the genusVismia

Vismiones and ferruginins, representatives of a new class of lypophilic anthranoids from the genusVismia were found to inhibit feeding in larvae of species ofSpodoptera, Heliothis, and inLocusta migratoria.     

Ethanol and (−)-α-Pinene: Attractant Kairomones for Bark and Ambrosia Beetles in the Southeastern US

In 2002–2004, we examined the flight responses of 49 species of native and exotic bark and ambrosia beetles (Coleoptera: Scolytidae and Platypodidae) to traps baited with ethanol and/or (−)-α-pinene in the southeastern US. Eight field trials were conducted in mature pine stands in Alabama, Florida, Georgia, North Carolina, and South Carolina. Funnel traps baited with ethanol lures (release rate, about 0.6 g/day at 25–28°C) were attractive to ten species of ambrosia beetles (Ambrosiodmus tachygraphus, Anisandrus sayi, Dryoxylon onoharaensum, Monarthrum mali, Xyleborinus saxesenii, Xyleborus affinis, Xyleborus ferrugineus, Xylosandrus compactus, Xylosandrus crassiusculus, and Xylosandrus germanus) and two species of bark beetles (Cryptocarenus heveae and Hypothenemus sp.). Traps baited with (−)-α-pinene lures (release rate, 2–6 g/day at 25–28°C) were attractive to five bark beetle species (Dendroctonus terebrans, Hylastes porculus, Hylastes salebrosus, Hylastes tenuis, and Ips grandicollis) and one platypodid ambrosia beetle species (Myoplatypus flavicornis). Ethanol enhanced responses of some species (Xyleborus pubescens, H. porculus, H. salebrosus, H. tenuis, and Pityophthorus cariniceps) to traps baited with (−)-α-pinene in some locations. (−)-α-Pinene interrupted the response of some ambrosia beetle species to traps baited with ethanol, but only the response of D. onoharaensum was interrupted consistently at most locations. Of 23 species of ambrosia beetles captured in our field trials, nine were exotic and accounted for 70–97% of total catches of ambrosia beetles. Our results provide support for the continued use of separate traps baited with ethanol alone and ethanol with (−)-α-pinene to detect and monitor common bark and ambrosia beetles from the southeastern region of the US.